Derekmj64
New Member
- Messages
- 7
- Age
- 37
- Location
- Holland
- Country
- USA
- Years Snowmobiling
- 28
- Snowmobile
- 2017 Polaris Switchback Assault 800
2002 Polaris 500 Edge X
I had a puzzling find on my snowmobile engine. Has anyone ever seen this on pistons? This is out of my 2017 Polaris 800 switchback assault engine (with 4,400 miles). I pulled the power valves out at the beginning of the week and noticed spherical dimples/craters on the tops of both pistons. It’s like someone put BBs in the cylinders (clutch side worse than the magneto side). I pulled the top end apart to find the clutch side piston has the dimples all the way around the perimeter and not anywhere else on the top of the piston and the Mag side had no where near as many, just isolated to one spot.
I have received feedback that the cause could be the main bearing coming apart and other people say detonation. The crank looks good from that I can see with the top end off, the rings are in good shape, wrist pin bearings are all intact and the ring locating pins are all there.
I am wondering if I caught a detonation issue before it got really bad? I’m scratching my head as to what could have caused this. I’ve never pulled pistons with this kind of damage.
I appreciate any input you may have.
I have received feedback that the cause could be the main bearing coming apart and other people say detonation. The crank looks good from that I can see with the top end off, the rings are in good shape, wrist pin bearings are all intact and the ring locating pins are all there.
I am wondering if I caught a detonation issue before it got really bad? I’m scratching my head as to what could have caused this. I’ve never pulled pistons with this kind of damage.
I appreciate any input you may have.
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